$FD50/64848: Initialise System Constants
Jump from $FCF5, $FF87:
FD50: A9 00 LDA #$00
FD52: A8 TAY
Jump from $FD5D:
FD53: 99 02 00 STA $0002,Y ; Unused
FD56: 99 00 02 STA $0200,Y ; BASIC Input Buffer (Input Line from Screen)
FD59: 99 00 03 STA $0300,Y ; Vector: BASIC Error Message
FD5C: C8 INY
FD5D: D0 F4 BNE $FD53
FD5F: A2 3C LDX #$3C
FD61: A0 03 LDY #$03
FD63: 86 B2 STX $B2 ; Pointer: Start Address of Tape Buffer
FD65: 84 B3 STY $B3 ; Pointer: Start Address of Tape Buffer
FD67: A8 TAY
FD68: A9 03 LDA #$03
FD6A: 85 C2 STA $C2 ; Start Address for LOAD and Cassette Write
Jump from $FD86:
FD6C: E6 C2 INC $C2 ; Start Address for LOAD and Cassette Write
Jump from $FD84:
FD6E: B1 C1 LDA ($C1),Y ; Start Address for LOAD and Cassette Write
FD70: AA TAX
FD71: A9 55 LDA #$55
FD73: 91 C1 STA ($C1),Y ; Start Address for LOAD and Cassette Write
FD75: D1 C1 CMP ($C1),Y ; Start Address for LOAD and Cassette Write
FD77: D0 0F BNE $FD88
FD79: 2A ROL
FD7A: 91 C1 STA ($C1),Y ; Start Address for LOAD and Cassette Write
FD7C: D1 C1 CMP ($C1),Y ; Start Address for LOAD and Cassette Write
FD7E: D0 08 BNE $FD88
FD80: 8A TXA
FD81: 91 C1 STA ($C1),Y ; Start Address for LOAD and Cassette Write
FD83: C8 INY
FD84: D0 E8 BNE $FD6E
FD86: F0 E4 BEQ $FD6C
Jump from $FD77, $FD7E:
FD88: 98 TYA
FD89: AA TAX
FD8A: A4 C2 LDY $C2 ; Start Address for LOAD and Cassette Write
FD8C: 18 CLC
FD8D: 20 2D FE JSR $FE2D ; Read / Set Top of Memory
FD90: A9 08 LDA #$08
FD92: 8D 82 02 STA $0282 ; Pointer: Bottom of Memory for Operating System
FD95: A9 04 LDA #$04
FD97: 8D 88 02 STA $0288 ; High Byte of Screen Memory Address
FD9A: 60 RTS
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Kernal-Reference:
LDA $FD93,X : $FCBD
LDA $FD94,X : $FCC3